1. Field of the Invention
This invention relates in general to a color television camera and particularly to a white balance control and memory system for use with a color television camera.
2. Description of the Prior Art
It is well known in the art of television cameras to provide a white balance adjusting circuit which includes a gain control circuit and the gain of the gain control circuit is varied so as to maintain the levels of the red, green and blue signals R, G and B equal while a color camera images a plate of an achromatic color such as white. Generally, circumferential light such as natural light and illumination light has an inherent color temperature and before electrically adjusting a color temperature adjusting circuit, suitable color temperature filters which are optical filters are selected for the rough adjustment.
In prior art color television cameras, only a single set of memories are provided for setting and storing the white balance control signal corresponding to a plurality of color temperature filters and it becomes necessary each time the filters are changed to adjust the white balance again. Especially with a portable color television camera, such as used for news gathering and which may be a portable color television camera which is moved between outdoors and indoors while recording the news the filter must be frequently changed.
In the prior color television cameras which have only a single memory new white balance data has to be taken each time a change in environment occurs. This results in time consuming adjustments which is a disadvantage for the operation of color cameras as, for example, for electronic news gathering.